The approaches described in this section could be pursued, but are not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, the approaches described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
Generally, link aggregation is a process of combining multiple network connections (known as links) in parallel to increase data throughput beyond what a single link could sustain, or to introduce redundancy for protection in case of link failures. As a result, the multiple aggregated links may function as though they were a single link within the network topology. Each aggregated link may represent physical links of a network, such as a power line or wireless connections, or virtual links of a network.
Consequently, link aggregation can take place at many different layers within the seven layer OSI model of computer networking. At layer 2, otherwise known as the data link layer, aggregation can occur between ports, virtual or physical, that transfer frames from one network device to another. In addition, at layer 4, otherwise known as the transport layer, links transferring segments, such as TCP connections, can also be aggregated.
In order to establish link aggregation between two devices of a network, both devices typically negotiate and agree upon the set of links to be aggregated. The process of negotiating the set of links is governed by an aggregation protocol. One aggregation protocol, known as Link Aggregation Control Protocol (LACP), performs link aggregation over links carrying MAC frames of the data link layer. LACP is described in a document entitled “IEEE Standard for Local and Metropolitan Area Networks—Link Aggregation,” authored by the IEEE Computer Society, the entire contents of which is hereby incorporated by reference for all purposes as if fully set forth herein. Another aggregation protocol, known as Port Aggregation Protocol (PAgP), performs link aggregation over a set of physical or virtual ports connecting two or more network devices. PAgP is described in a document entitled “Port Aggregation Protocol”, authored by Cisco Systems, Inc., San Jose, Calif., the entire contents of which is hereby incorporated by reference for all purposes as if fully set forth herein.